1. Field of the Invention
The present invention relates to a four-directional switching device which performs switching in response to pressing operations in four directions of an operating member.
2. Description of the Related Art
Conventionally, a mirror switch is typically employed as such a four-directional switching device in the related arts, in which a driver can remote-control from his seat left and right mirrors mounted on a body of a vehicle, as disclosed in Japanese Patent Application Publication No. 10-106397 further described below.
FIG. 6 is a cross-sectional view of a four-directional switching device of the related art taken along one direction (6—6 direction of FIG. 8 to be described later), FIG. 7 is a cross-sectional view of the four-directional-switching device taken along other direction (7—7 direction of FIG. 8 to be described later), and FIG. 8 is an exploded perspective view of the four-directional switching device.
This four-directional switching device is mainly comprised of a casing forming an outer shell of the switching device, an operating member 23 exposed from an opening 22 formed in the casing 21, a support member 24 supporting the operating member 23 tilted in various directions, a print substrate 25 fixed on the casing 21, a rubber sheet 26 mounted on the print substrate 25, and four sliders 27 interposed between the rubber sheet 26 and the operating member 23.
The operating member 23 is comprised of a cover 28 formed of a synthetic resin protruded from the opening 22 and a rotating member 29 formed of a synthetic resin mounted on the other side of the cover 28, and the cover 28 and the rotating member 29 are formed into one body as described later. Four display portions 28a representing tilt directions are formed on a surface of the cover 28, and four restriction piece 30 are formed into one body which are protruded downward from a center portion of the other side of the cover 28 as shown in FIG. 6, and these restriction pieces 30 are disposed at an equal interval of about 90°. In addition, four suspension pieces 31 are formed into one body, which are protruded downward from an outer side of the restriction pieces 30. In the meantime, four stoppers 32 are formed into one body which are protruded upward on the surface of the rotating member 29 as shown in FIG. 6, and these stoppers 32 are connected to each other as a ring type, and four interconnections 33 extend from between stoppers 32 toward a center of the rotating member 29, and a spherical member 34 is formed in an interconnecting position of each interconnection 33. As a result, a portion surrounded by the spherical member 34, each of the interconnections 33 and each of the stoppers 32 becomes a transparent hole 35. In addition, four elastic pieces 36 are formed into one body which are protruded upward from an outer side of respective stoppers 32, and these elastic pieces 36 are snapped in the suspension pieces 31, respectively so that the cover 28 and the rotating member 29 are formed into one body. In this case, each restriction piece 30 is inserted to the corresponding transparent hole 35, and a predetermined spacing is ensured between the spherical portion 34 and each of the restriction pieces 30.
The support member 24 is formed of a synthetic resin and is fixed on the casing 21 using a proper means such as a snapping-in means. As shown in FIG. 8, four support pieces 38 are formed into one body in a center portion of the support member 24 while being sectioned into four by a cross-shaped slit 37, and a guide portion 40 is formed at a leading end of an extension wall 39 which extends outward from a bottom portion of each slit 37. Each support piece 38 is curved, the spherical portion 34 is put into the operating member 23 from a top end of each support piece 38 described above, and each interconnection 33 is inserted into the corresponding slit 37, and an inner side of each restriction piece 30 is in contact with an outer surface of the support piece 38 while an outer side of each restriction piece 30 is in contact with each stopper piece 32. In addition, the slider 27 is inserted to each guide portion 40 to be guided upward and downward directions. The slider 27 is formed of a transparent light-guiding material such as an acrylic resin, and its top end is in contact with a bottom surface of the rotating member 29 while its bottom end is in contact with a hollow protruding portion 44 of the rubber sheet 26 to be described later.
A lamp 41 as a light source is mounted and a plurality of fixed contacts 42 are formed at an equal interval of about 90° centered on the lamp 41 on the print substrate 25. In the meantime, a hole 43 for allowing the lamp 41 to penetrate is formed in the rubber sheet 26 while four hollow protruding portions 44 are formed to be bulged at an equal interval of about 90° centered on opening 43, and four sets of switching elements has each movable contact 45 formed on an inner bottom portion of each hollow protruding portion 44 and each fixed contact 42 on the print substrate 25. The rubber sheet 26 is mounted on the print substrate 25, and both of the rubber sheet and the print substrate are positioned by pin, hole, and so forth which are not shown.
For assembling it comes to assemble the multi-directional switching device constructed as above, the slider 27 is first inserted into each guide portion 40 of the support member 24, and the support member 24 is fixed to an inner surface of the casing 21. The spherical portion 34 is fixed inside from a top end of each support piece 38 while each interconnection 33 of the rotating member 29 is forced to be in place with respect to the corresponding slit 37 of the support member 24. At this time, since the cover 28 is not formed into one body with the rotating member 29, each support piece 38 elastically deforms the transparent hole 35 outward and returns to its original state while the spherical portion 34 is fixed within each support piece 38, so that the spherical portion 34 may be snapped in each support piece 38. Each restriction piece 30 of the cover 28 is then forced to be in place with respect to the corresponding transparent hole 35, and each suspension piece 31 is snapped in the elastic piece 36 after the cover 28 is pressed against the rotating member 29, so that the cover 28 and the rotating member 29 are formed into one body. As a result, each restriction piece 30 is in contact with an outer surface of each support piece 38 so that the extension of the support piece 38 is prevented, and the spherical portion 34 is surely supported by each support piece 38. Furthermore, since the stopper piece 32 is disposed at an outer side of each restriction piece 30, the outward deformation of the restriction piece 30 is hindered by the stopper piece 32, so that the extension of the support piece 38 may be surely prevented.
Next, an operation of the multi-directional input switch device assembled as described above will be described. When a peripheral portion of the cover 28, for example, a right side of the cover 28 of FIG. 7 is depressed from its non-operating state shown in FIGS. 6 and 7, the spherical portion 34 is supported by the support piece 38 of the support member 24, so that the cover 28 and the rotating member 29 (i.e. operating member 23) are tilted in a clockwise direction of FIG. 7 centered on the spherical portion 34. In addition, the slider 27 positioned right of FIG. 7 is depressed by the rotating member 29 to thereby press the hollow protruding portion 44 of the rubber sheet 26 which is positioned right below the slider 27, so that the hollow protruding portion 44 is buckled to be deformed to generate a click sense while the movable contact 45 comes in contact with the opposing fixed contact 42 to thereby being in a switching on state. However, when hand is taken off from the cover 28 in such a tilted state, by means of the elastic force of the hollow protruding portion 44 of the rubber sheet 26, a portion of the rotating member 29 moving downward by the slider 27 is pushed upward so that the operating member 23 returns to its original state as shown in FIGS. 6 and 7. As a result, the movable contact 44 which was in a contact state is spaced from the fixed contact 42 to thereby being in a switching off state again. In addition, when the lamp 41 is turned on at night or in dark places, the light from the lamp 41 is guided toward the rear surface of the cover 28 through each slider 27 so that each display portion 28a is illuminated.
However, in the related art, the operating member 23 is comprised of the cover 28 and the rotating member 29, in which the spherical portion 34 of the rotating member 29 (operating member 23) is snapped in each support piece 38 of the casing 21 and each support piece 38 is prevented from being extended by the restriction piece 30.
Accordingly, only the snap interconnection between the spherical portion 34 and each support piece 38 may prevent the spherical portion 34 from being dislocated from each support piece 38, so that the spherical portion 34 may be dislocated from each support piece 38 when a high impact is forced to the operating member 23 or the like, which may lead to a dislocation of the operating member 23, thereby making it difficult to enhance the mechanical intensity.
In addition, the slider 27 acts as a light guiding member of guiding lights to the operating member 23, however, four sliders 27 are required, and it is difficult to ensure that lights are guided. Furthermore, there exists a support piece 38 and a supporting portion from the casing 21 of the support member 38, whereby making it difficult to illuminate them with only one light guiding member disposed at their center.